Process for the conversion of petroleum oil



C. F. DUBBS PROCESS FOR THE CONVERSION OF PETROLEUM OIL Original Filed Sept. 13, 1922 May 4, 1937.

SLK 7% Patented May 4, 1937 PROCESS FOR THE CONVERSION F PETROLEUM OIL praise 'r oFFicE Carbon P. Dubbs, Wilmette, Ill., assigner, byy

mesne assignments, to Universal Oil Products Company, Chicago, Ill., a corporation of Dela- Continuation of application Serial No. 587,883,

September 13, 1922.

This application May 14,

1930, Serial No. 45,2,199l/2. Renewed June 27,

1934 y Claims.

Thisinvention relates to a process and apparatus for the conversion of petroleum` oils and relates more particularly to the conversion of oils under substantial pressure, to change the oils 5 from relatively high boiling point oils to low boiling point oils similar to Vdistillates having the characteristics of gasoline and the like.

This application is a continuation of my applicationgl led September 13, 1922, Serial No.

Among the objects ofthe invention are to provide a process in which utilization of the heat for prey-heating andthe dephlegmation of the `oil vaporsl in the refluxing `zone combine to form a more efficient process ,in operation, and` giver more satisfactory results in the products obtained.

The single gure is a diagrammatic sidefelevational view ofthe apparatus with parts broken away in order to disclose more clearly the features of the process.

Referring to the drawing, the oil stock to be treated is introduced from any convenient extraneous source through the line I, and is charged by means of the pump 2 through the line 3 controlled by the valve 4 andv may be directed'through the pre-heating coil 5 and thence through lines 6 and 'I to the heating coils 8 by pro-per manipulation of the valves 4, 45, 43 and 44, or by closing the valve 4 and opening the valveS into s lines I 0 the raw oil charge may be introduced land circulated through the coil I I. This preheating coil is situated just above that part of the dephlegmatorinto which the vapors are introduced, and terminatesin a perforated circular pipe or hose I2 discharging the preheated oil into vertically arranged perforated pans I3 through which the oil percolates in a broken up condition, passing off through the bottom of the dephlegfmator I4, through the dephlegmator leg I5. The draw-off line l, controlledv by'valve I 6 directs the oil from the bottom of the dephlegmator leg i I5 to the heating coils 8.

The heating coils are mounted in a side fired furnace I1 and while circulating through the coils 8, the oil is raised to a conversion temperature and passes from the heating coils through the transfer line I 8 to the expansion chamber I9. 'Ihe expansionchamber has residuum drawoif lines 20 and 2| controlled by valves22 and 23. In this expansion chamber, the oil is permitted to collect in a substantial body and during 'a digestion and vaporization period the oil vapors are evolved which pass off through the 55 line 24 controlled by the valve 25 to the dephleg- (ol. 19e-48) with the returned distillate which is recirculated from the receiver 26 through the lines 2l and 28 into the top of the dephlegmator through the coil 29 and spray pipe 30. The oil vapors that remain uncondensed, arriving at the top of the dephlegmator pass oit through the vapor line 3l controlled by valve 32 to a water condensing coil 33 mounted ln condenser box 34. The discharge end of the condenser coil is connected by pipe 35 regulated by valve 3B to the receiving tank 26 which is equipped with a pressure relief valve `3l, liquid draw-off valve 38 'and liquid level gauge 39.

The distillate as explained, may be returned through the line 2'I and charged by means of the pump 4I) through line 2B controlled by valve 4I to y the top of the dephlegmator where it may be passed as a cooling medium through the valve into the coily 5 and thence through the line 42 controlled by valve 43 to any convenient storage tank, or returned by closing the valve 43 and opening the valve 44 to the line 'I where it is recirculated with a charging stock to the heating coil. y 1

An alternate method of returning the distillate is to close the valve 45 and open the valve 4I thereby introducing the distillate to the coil 29 and discharging it from the perforated pipe 3i! into the upper pan oi' the dephlegmator. These alternative methods of controlling the temperatures in the dephlegmator or refluxing tower furnish a very accurate control of the temperature therein whereby the rellux condensate separated from the vapors may be accurately controlled and the character of the distillate passing over to the receiver, regulated to predetermined ranges.

The introduction of the raw oil below the vapor pipe in the refluxing column prevents the shocking of the light ends contained in the charging stock which usually results in their being carried over with the heated oil vapors to the condenser and receiver. By utilizing the apparatus eX- plained, the charging' stock is contained in a closed coil during its circulation through the heated oil vapors whereby the pre-heating action is not attended by intimate contact between the highly heated vapors and the volatile products of the charging stock, and it is not until the charging stock has reached a level below that portion of the dephlegmator where the oil vapors 5 are introduced that it is discharged into the dephlegmator proper.

Below this point the temperatures are less, due to the returned distillate and separated condensate gravitating from the upper portions of.

0 the dephlegmator so the oil discharged in this manner will get the pre-heating effect and at the same time will not be relieved of its lighter ends which are objectionable when carried over with the vapors to be combined with the distillate 5 in the receiver.

The character of the apparatus may be varied dephlegmator to pass through a coil therein as a refluxing medium, discharging said distillate from the coil into the dephlegmator at a point near which the oil vapors are discharged from the dephlegmator, introducing raw oil to the dephleg- 5 mator to pass through a coil above the point at which the vapors are introduced to the dephlegmator, and in discharging the raw oil from said coil -into the dephlegmator at a point below the point of introduction of said vapors, and in continuously supplying raw oil and reflux condensate to the elongated passageway for treatment.

2. A conversion process which comprises subjecting hydrocarbon oil to cracking conditions of temperature and pressure in a heating coil, separating the heated oil into vapors and residue in a separating chamber, introducing the vapors to a fractionating column at an intermediate point in the height of the column substantially.

'above the bottom thereof, introducing preheated charging oil for the process to the column below said point but a substantial distance above the bottom of the column and passing it downwardly to the bottom of the column, whereby to release lighter fractions of the charging oil out of contact with the vapors being introduced at said intermediate point, fractionating the vapors in the upper portion of the column above said point to condense heavier fractions thereof, removing the fractionated vapors from the top of the column and nally condensing the same, introducing a portion of the resultant final condensate into contact with the vapors undergoing fractionation in the upper portion of the column as a refluxing medium for the vapors, and supplying admixed reflux condensate and unvaporized charging cil from the bottom of the column to the heating coil.

3. A conversion process which comprises subjecting hydrocarbon oil to cracking conditions of temperature and pressure in a heating coil, separating the heated oil into vapors and residue in a separating chamber, introducing the vapors to a fractionating column at an intermediate point in the height of the column substantially above the bottom thereof, passing charging oil for the process in indirect heat exchange with the vapors in the column above said point, then introducing the thus preheated charging oil to the column below said point but a substantial distance above the bottom of the column and passing it downwardly to the bottom of the column, whereby to release lighter fractions of the charging oil out of contact with the vapors being introduced at said intermediate point, fractionating the vapors in the upper portion of the column above said point to condense heavier fractions thereof, removing the fractionated vapors from the top of the column and finally condensing the same, introducing a portion of the resultant final condensate into contact with the vapors undergoing fractionation in the upper portion of the column as a reiiuxing medium for the vapors, and supplying admixed reflux condensate and unvaporized charging oil from the bottom of the column to the heating coil.

4, The process as defined in claim 2 further characterized in that said portion of the final condensate, prior to its introduction into contact with the vapors in the upper portion of the co1- umn, Vis passed in indirect heat exchange with the vapors being removed from the top of the column.

5. The process as defined in claim 3 further characterized in that said portion of the final condensate, prior to its introduction into contact with the vapors in the upper portion of the co1- umn, is passed in indirect heat exchange with the vapors being removed from the top of the column.

CARBON P. DUBBS. 

